Dates currently under suspicion:
1989✔️1989/12/29 Cleveland, OH Phantasy Theatre - <s>Not sure if they played 2 dates here. Dec. 28 is definitely confirmed though, by the NIN tour manager, Mark O'Shea. https://www.clevescene.com/cleveland/getting-physical/Content?oid=1492360<br />Mark O'Shea: https://www.linkedin.com/in/markloshea https://www.goodyeartheater.com<br />Newspaper clipping confirming Dec. 29 date: https://twitter.com/ninlive/status/1153807351071162370</s><br />
Probably only one date: https://happinessinheresy.com/nine-inch-nails-concert/cleveland-december-29-1989/
1990/01/28 Portland, OR Pine Street Theatre - While JAMC played this date, NIN probably didn't support, because of travel time involved. The first support date was probably Warfield in SFO.
1990✔️1990/03/27 Atlanta, GA - <s>Were there 2 dates for The Roxy?</s> - yes, newspaper article confirms it [https://happinessinheresy.com/nine-inch-nails-concert/atlanta-march-27-1990/]
1990/04/03 Phantasy - Were there 2 dates for Cleveland? (probably not the 4th)
1990✔️1990/04/14 Washington, DC Lisner Auditorium - <s>Did this one happen? The 9:30 Club headliner show the next night definitely did.</s> - Manifesto was opener. NIN did not open. [https://web.archive.org/web/20190927020313/http://www2.gwu.edu/~alumni/yearbooks/CHERRY_TREE_1990_ST.pdf]
1990✔️1990/04/17 Toronto - Concert Hall or RPM Club? Setlist.fm user says it was RPM club. [https://groups.google.com/d/msg/alt.music.nin/dH6Dscu98wc/52RxD_tASqgJ alt.music.nin poster] says first NIN gig in Toronto was RPM Club. UPDATE: Solicitations were for RPM: https://happinessinheresy.com/nine-inch-nails-concert/toronto-april-17-1990/
1990/07/12 Neptune, NJ, Green Parrot - This date originally solicited [https://happinessinheresy.com/nine-inch-nails-concert/philadelphia-july-12-1990/ 1.5 months] before as Chestnut Cabaret. Likely replaced by Drexel Univ. concert. Drexel and Chestnut Cabaret are located within 4 blocks of each other, so it's unlikely both happened. This guy's [http://musictravel.free.fr/concerts/concerts90.htm concert list] shows that he went to many early NIN shows around Philly and to many shows at the Chestnut Cabaret. If NIN had played Chestnut, he would have been there. Instead, he only went to Drexel. So I think that confirms that Chestnut was probably cancelled, maybe replaced by Drexel, and Green Parrot slotted into the original Chestnut date.
1990/07/25 St. Louis, MO 1227 - unlikely they played the same venue within a month of each other. The 6/21 date is confirmed with newspaper solicits, and this one has none. Only possibility is if the 6/21 date got postponed for some reason (first night of the tour) and made up on 7/25? NIN Historian listed 7/25 without any corroboration, so maybe he knew the concert took place, but not the date, and slotted it in somewhere it might fit, but he didn't know it was at the beginning of the tour? UPDATE: There is zero for "1227 nine inch nails" on newspapers.com in July 1990, and tons in June 1990, so I think this date is just flat out wrong.
1991✔️1991/01/22 Washington, DC 9:30 Club (1 AM show) - <s>What was the proof for 2 shows on the same night? I forget.</s> 9 PM and 11 PM shows: https://happinessinheresy.com/wp-content/uploads/2019/08/026-AUE-1991-01-28-001-SINGLE-1.jpg
1991✔️1991/02/06 Hollywood, CA Stardust Ballroom (Helter Skelter) - <s>This seems to be a spurious 2nd date, maybe due to the VHS circulating? Ask Richard Alan White about what the date on his filming was, and if there were 2 shows.</s> [https://happinessinheresy.com/nine-inch-nails-concert/los-angeles-05-february-1991/ Poster] confirms 2nd date added.
1991✔️1991/08/29 Koln, Germany Luxor - <s>Show was solicited, but apparently may have been cancelled. The show has been removed from setlist.fm already. Why?</s> [http://ninlive.com/archives/1991.html NIN Live] received information directly from the promoter that it was Cancelled due to Trent's Voice.
1994✔️1994/03/18 Phoenix, AZ The Roxy - <s>Did the second show happen at The Roxy? NIN Historian originally had The Grind. Some guy on setlist.fm also claims it was The Grind, though his anecdote does not actually provide any evidence to back that up. happinessinheresy's newspaper clipping shows both shows were sold for The Roxy, so if it changed, it was a last-minute venue change.</s> [http://nintourhistory.com/uploads/tickets/154422523288image.jpg Ticket stub] confirms 2nd show was at the Roxy.
1994/03/27 Honolulu, HI After Dark - This was solicited in the newspaper, up to the day before the show, as a single date, Mar. 26, at After Dark. There is a ticket stub for the 26th on nintourhistory, but nothing for the 27th. Need to talk to Bill Rose, who did security there, about the show(s).